TacFire 3/4 inches High Pica tinny Riser Mount for Scopes and Red Dot Sights TacFire Official Product , This Riser allows the owner to have extra clearance when mounting an optic with a large objective lens. It solidly mounts onto your flat top receiver and allows you to mount your scope on top, via the US Forces 1913 picatinny rail using stanag rings. It has an opening underneath to allow the user to utelize their iron sights if need be. Industrial Grade Aluminum Solid Construction Black Finish Attaches To Your Mil Standard 1913 Picatinny Rail On A Flat Top Receiver US Force 1913 Picatinny Rail Accepts Standard Weaver Rings Or Stanag Rings See Through Design Allowing You To Use Your Peep Sights Two thumb screws on the side with holes that let you to tighten them down by using an Allen wrench Top Rail 5.25" Long with 13 Slots , Bottom Mount 4.88" Long , Weight : 4.3 Oz Finish : Matt Black